Single Photon Emission Computed Tomography (SPECT) is a powerful, non-invasive medical imaging technique which provides an image of the three-dimensional distribution of radionuclide in any slice through an organ under study in the body. These images allow investigation of metabolism in the region being studied and are also a useful tool for understanding the functioning of the organs, as well as diagnosing symptoms of diseases such as cancer, myocardial ischemia, Alzheimer's disease, head trauma, and stroke. Scintillation crystals (such as NaI:TI) coupled to photomultiplier tubes are typically used as detectors in SPECT systems and the imaging performance of the system is often limited by the characteristics of the available scintillation materials. In order to overcome the limitations in the existing detectors, the goal of the proposed research is to investigate a promising new scintillation material which shows higher light output, faster response, and higher stopping efficiency compared to NaI(T1) crystals. The Phase I project will be aimed at demonstrating the feasibility of producing large crystals of the new scintillation material and applying such crystals to radionuclide imaging.